Bought 2 RE audio 18 SX's....... and....

[Bassman999 10+ year member]

The SX use Aluminum which has a greater heat dispersion than copper.And his 10 cubic ft is before displacements which after displacements is WAY TOO SMALL.

Wouldn't the box being too small limit output and frequency response only , and not cause thermal issues?

Knowledgestick are the subs hot to the touch only, I mean do they smell?

 

[Annnarbor84 5,000+ posts]

It seems as though I am late for another fail session:crap: Cannot stress enough the importance of properly built box and sq in or port. 16 sq in. of port per cube ftw

 

[Annnarbor84 5,000+ posts]

Wouldn't the box being too small limit output and frequency response only , and not cause thermal issues?
Knowledgestick are the subs hot to the touch only, I mean do they smell?

Box built wrong can cause undue stress to the subs. Possibly what is going on here

 

[mcsoul 10+ year member]

With only 10 cubes gross, you could have left it sealed, put different subs in the box and come out ahead. USAMPFREAK is right about the required box size and port area for the 18" SX's.

You could have put $120 18" Dayton's in there and sounded good sealed.

You still may be able to salvage things with some MJ's, but what are those port dimensions?

 

[knowledgestick 10+ year member]

the box is alot larger than 10cu, that was a very safe guess when i first made it, and i need to make it clear that the box is likely atleast 3 cubic feet larger than that.

it is more like 13-14 before the subwoofers are put in.

here is a video of myself testing them with the multi-metre, aswell as showing the ported specs, and also showing a general estimation of my box's cubic feet.

http://blip.tv/file/1988262

just with those measurements provided in my video not including the smaller areas of my box, it is around 14 cubic feet before woofers.

 

[knowledgestick 10+ year member]

i would also like to thank everybody for their help along the way and trying to diagnose the problems, i am sure we will get to the bottom of what is causing the over-heating, and one way or another i will get it resolved.

They get very warm to the touch, and have only ever smelt once. right in the center of the dust-cap gets extremely hot to the point where it is almost maluable and soft.

no i am not an expert on car audio, i am just trying to make thease things work. They where my birthday presants to replace my last 18''s and all i want is for them to work propperly and to my expectations

( not over-heating faster than my old subs ) and i will be happy.

I am taking future shop to small claims court for their negligence in the first install, to get the 600 dollars back i spent on this new box. Hopefully if anything needs to be done, i can use the money i re-gain from this to put towards making it right, witch is what i thought was getting done this time.

 

[knowledgestick 10+ year member]

Wouldn't the box being too small limit output and frequency response only , and not cause thermal issues?
Knowledgestick are the subs hot to the touch only, I mean do they smell?

This is what i thought aswell, and yeah they CAN get stinky, its only ever happened once after the porting, and it was minimal, i am being very careful with them and babying them.

But the previous tests, resulted in no stink, but extremely hot center of the dust cap.

Will post back with more information as i gather it. Please ask questions and feel free to help, i appreciate it alot.

-andrew

 

[snfsh79077 10+ year member]

after watching your video I was correct. You are clipping the crap out of that amp. You don't match the gain with what preamp voltage you have. You set them correctly with a dmm. (sqrt*[watts*impedance]) Also your ssf is set wrong. It is not supposed to be set above tuning, it's supposed to be a few hz below tuning. You said the tuning of the box is 29-30 so you would want your ssf around 27hz.

Also I still don't believe that that box is 14 cubes. Have you seen a box that is 14 cubes with a correct port size and after displacement?

 

[Bassman999 10+ year member]

I am going to guess, based on the the tape measure measurements around 10.3 net tuned to just over 36 hz 100^2 port. While that isnt optimum, I think it is on the low side of adequate. Lots of ppl think 16^2 per ft^3 box volume, and that is great for spl, but may not be needed for daily. Lots of ppl believe that 10-12^2 per ft^3 for daily is fine.

 

[snfsh79077 10+ year member]

I am going to guess, based on the the tape measure measurements around 10.3 net tuned to just over 36 hz 100^2 port. While that isnt optimum, I think it is on the low side of adequate. Lots of ppl think 16^2 per ft^3 box volume, and that is great for spl, but may not be needed for daily. Lots of ppl believe that 10-12^2 per ft^3 for daily is fine.

12-16 square inches per cubic foot is the medium for a slot port. If he says his box is 14 cubes then it would need 168 square inches minimum...if it is 10 cubes which is more likely then it will need a minimum or 120 square inches. Either way port area is still to small for those subs.

with that being said fix what I stated before and you will see a noticeable difference. You box is still not correct though

edit:

a rough design of a box that is 20" high x 39" wide x 28" deep with 111 sq inches of port area tuned to 29hz is only 8.6 cubic feet before sub displacement and w/o bracing. Meaning that your is probably not even 10 cubic feet...

 

[knowledgestick 10+ year member]

well i just tested them again, and they got hot at the center of the dust cap and i figured if they where that hot at the cap the drivers must be extremely hot, so i reached down into the vented box and to my suprise the drivers wernt all that warm even up into the center where i could reach with my fingures.

i dont get why the things are heating up and stinking so bad, the box may not be to spec but its still a big *** box, and has alot of port for breathing.

Are R-E audio subwoofers really that finicy ? it says in their manuals they are built for brutality and that they build there gear for "real world use"

it would seem they require some serious pampering if it is due to the box being a couple cubic feet too small.

I have fiddled with the gain, and put that to 12'oclock and had it a little past 12 o'clock, and the system is not that loud at all.

The system doesnt really seem to get loud unless the level is turned to where i had it in the video.

And even if it is turned down less, they still heat up and get stinky it just takes a little longer..

anyways, what would you guys sugest ? should i take them out of the trunk and have a hole new box rebuilt that uses up basicly every square inch of my trunk for airspace or what ?

i did not think that thease things would be such a hastle after dealing with MA audio and their woofers suposedly being "tough as hell" i figured thease SX's would be perfect and wouldnt cause any problems, i was wrong.

I hope i can get this resolved and fixed.

 

[knowledgestick 10+ year member]

I am going to guess, based on the the tape measure measurements around 10.3 net tuned to just over 36 hz 100^2 port. While that isnt optimum, I think it is on the low side of adequate. Lots of ppl think 16^2 per ft^3 box volume, and that is great for spl, but may not be needed for daily. Lots of ppl believe that 10-12^2 per ft^3 for daily is fine.

if you use those specs i gave out in the video on bassbox pro it says the boxvolume is over 14 cubic feet, that is where i got that figure.

and like i said, that does not even include all the tiny little nook up by the amplifier.

Is it the SX's only that are like this with sealed/ported boxes ? i am at a loss... i have never experianced this before..

Like ive said many times, i had my amplifier setup that way with the MA audios and they pounded for around a half year before the one with a PL held together dust cap finally gave way, i cant see why we are making all thease box/porting excuses for thease SX's heating up so fast i just dont get it.

The only differance is my MA audio Xe's where inverted.

 

[snfsh79077 10+ year member]

well i just tested them again, and they got hot at the center of the dust cap and i figured if they where that hot at the cap the drivers must be extremely hot, so i reached down into the vented box and to my suprise the drivers wernt all that warm even up into the center where i could reach with my fingures.
i dont get why the things are heating up and stinking so bad, the box may not be to spec but its still a big *** box, and has alot of port for breathing.

Are R-E audio subwoofers really that finicy ? it says in their manuals they are built for brutality and that they build there gear for "real world use"

it would seem they require some serious pampering if it is due to the box being a couple cubic feet too small.

I have fiddled with the gain, and put that to 12'oclock and had it a little past 12 o'clock, and the system is not that loud at all.

The system doesnt really seem to get loud unless the level is turned to where i had it in the video.

And even if it is turned down less, they still heat up and get stinky it just takes a little longer..

anyways, what would you guys sugest ? should i take them out of the trunk and have a hole new box rebuilt that uses up basicly every square inch of my trunk for airspace or what ?

i did not think that thease things would be such a hastle after dealing with MA audio and their woofers suposedly being "tough as hell" i figured thease SX's would be perfect and wouldnt cause any problems, i was wrong.

I hope i can get this resolved and fixed.

You need to set your gain with a dmm before you can rule it out. just because you turned it down to 12 o clock doesn't mean you still aren't clipping it. Also your box is about the size one of those subs would need and your trying to run two of them in it. The subs aren't finicky, just put them in a proper enclosure with clean power and they will perform as advertised. You apparently don't have the room for both so I would advise selling both and getting something better for your application or selling one and having a new baffle made for just the one.

 

[snfsh79077 10+ year member]

if you use those specs i gave out in the video on bassbox pro it says the boxvolume is over 14 cubic feet, that is where i got that figure.
and like i said, that does not even include all the tiny little nook up by the amplifier.

Is it the SX's only that are like this with sealed/ported boxes ? i am at a loss... i have never experianced this before..

Like ive said many times, i had my amplifier setup that way with the MA audios and they pounded for around a half year before the one with a PL held together dust cap finally gave way, i cant see why we are making all thease box/porting excuses for thease SX's heating up so fast i just dont get it.

The only differance is my MA audio Xe's where inverted.

Are you sure you aren't using your external dimensions as internal dimensions? Also are you factoring in port and sub displacement? Your box isn't near 14 cubes

 

[knowledgestick 10+ year member]

i turned the subsonic down a bit as sugested a bit below the box frequency, and am experiancing far less heating up, i am also about to adjust the gain via the metre, i have a chart that was given to me that lists the # that should read out on the metre for X amount of RMS, so i will set that now and see if it clears things up.

I am going to have to get he box issues dealt with if i want to get the maximum potential out of thease woofers, so i will likely have my hole trunk re-done to fit thease things.

IF that is possible, if not i will have to find somthing that can work in a smaller box, and handle the RMS i am trying to throw at the pair.

it is just very frusterating when my MA audio subwoofers where basicly no hastle at all and handled the power without problems, and then i get thease expecting even better preformance and they are just a hastle.

I thought they would atleast preform half deciant if i could get the box as close to spec as possible, i had no idea they would be over-heating and causing thease problems unless the enclosure was made exactly to spec.

I am going to have to see what i can do with my trunk, i dont want to go through the hastle of selling thease woofers i only bought them to replace my last ones.

I dont want to have to get rid of them, and then re-purchase a new pair that can handle 1300 rms each and fit in that enclosure, I would probably have to spend alot more money and it would be a huge hastle.

I think i am going to take them out for now, and wait until i can get a box professionally designed and fit for my trunk to maximize air-space, because with 17 cubic feet of trunk ( not including the wheel well ) i am sure with the fibre glass tub in the bottom, and using up most of my trunk near spec could possibly be achived.

Argh i have no idea.